摘要:

AbstractThe Grignard reagent made from p‐cyclohexyl m‐chloroiodobenzene is carbonated with14CO2to give 3‐chloro 4‐cyclohexyl benzoǐc acid (radioactive yield 50 %). This acid is transformed into the corresponding chloride with thionyl chloride. Condensation of the chloride with tris‐(trimethylsilyl) 1‐lithio‐1,1,2 ethane tricarboxylate gives after hydrolysis 4‐(3‐chloro 4‐cyclohexyl phenyl) 4‐oxobutyric acid 4‐14C with an overall yield of 41 % based on barium carbonate. (Specific

ISSN:0362-4803    

DOI:10.1002/jlcr.2580120402

出版商:John Wiley&Sons, Ltd.    

年代:1976

数据来源: WILEY

摘要:

AbstractItaconic acid‐4‐14C has been prepared by condensation of sodium cyanide14C with ethyl α‐bromomethyl acrylate and hydrolysis of the intermediate ethyl α‐(cyanomethyl) acrylate.Itaconic anhydride‐4‐14C has been used in Friedel‐Crafts reactions with respectively biphenyl, 2‐chlorobiphenyl, 4‐chlorobiphenyl for the preparation of 4‐biphenyl‐4‐oxo‐2‐methylene butyric acid‐4‐14C and the corresponding‐2′chloro

ISSN:0362-4803    

DOI:10.1002/jlcr.2580120403

出版商:John Wiley&Sons, Ltd.    

年代:1976

数据来源: WILEY

摘要:

Abstract2,6‐Dichlorobenzylidene aminoguanidine acetate, a new antihypertensive agent, was labelled with14C at the benzal position for metabolic studies. The key reaction involved the reduction of the sterically hindered 2,6‐dichlorobenzonitrile [cyano‐14C] with lithium aluminum hydride to 2,6‐dichlorobenzaldehyde [carbonyl‐14C]. The labelled nitrile was prepared by a Sandmeyer reaction employing 2,6‐dichloroaniline and K14CN. Further reaction of the labelled aldehyde with aminoguanidine bicarbonate produced the desired radio

ISSN:0362-4803    

DOI:10.1002/jlcr.2580120404

出版商:John Wiley&Sons, Ltd.    

年代:1976

数据来源: WILEY

摘要:

AbstractFor mass spectrometric studies 1‐phenyl‐2‐phenyl‐1‐13C‐ethene‐1‐13C (trans‐stilbene) was synthesized from acetic‐1‐13C acid and acetic‐2‐13C acidviamethylcyclohexene‐1‐13C and ‐α‐13C and toluene‐1‐13C and ‐α‐13C. No scrambling of the label was observed during the aromatization step. The labeled stilbene was converted into 1‐phenyl‐2‐phenyl‐1‐13C‐ethane‐1‐13C (bibenzyl), 2‐phenyl‐3‐phenyl‐1‐13C‐oxirane‐2‐13C (trans‐stilbene oxide),meso‐1,2‐dibromo‐1

ISSN:0362-4803    

DOI:10.1002/jlcr.2580120405

出版商:John Wiley&Sons, Ltd.    

年代:1976

数据来源: WILEY

摘要:

AbstractL'hexaméthylmélamine (noyau)14C‐2‐4‐6 (HMM14C), un nouvel agent antitumoral, a été synthétisée à partir de l'urée14C en 2 stades. L'urée14C est cyclisée dans l'o‐dichlorobenzène en acide cyanurique14C‐2‐4‐6, purifié par chromatographie sur colonne d'échangeur d'ions Séphadex SP C‐25. L'amination directe de l'acide en présence de HMPT et de diméthylamine donne l'HMM14C. Aprés purification par chromatographie sur colonne de gel de silice d'adsorption, on obtient. l'HMM14C avec un rendement radioactif global de 18 % par rapport à l'urée14C,

ISSN:0362-4803    

DOI:10.1002/jlcr.2580120406

出版商:John Wiley&Sons, Ltd.    

年代:1976

数据来源: WILEY

摘要:

AbstractA mild exchange labeling procedure utilizing O‐deuterated or O‐tritiatedt‐butanol with sodium catalysis afforded isotope exchange in the α‐hydrogen position of the amide N‐t‐butyl‐2‐(5‐benzyloxy‐6‐hydroxymethyl‐2‐pyridyl)‐2‐hydroxy‐acetamide, thereby extending the utility of this approach with ketones to poor enolizers that are base labile. Complete label retention accompanied the subsequent steps of reduction and debenzylation to 2‐hydroxymethyl‐3‐hydroxy‐6(l‐hydroxy‐2‐t‐butylaminoethyl)‐pyridine dihydrochloride (pirbuterol hydrochloride)‐2H or ‐3H, in 15‐18% overall yield at the 4 mmole level. Deuterium incorporation was estimated to be 39%; a specific activity of 206 μc/mg was achieved by radiolabeling. A radiochemical and chemical purity of>99.5% was established. Tritium label stability was demo

ISSN:0362-4803    

DOI:10.1002/jlcr.2580120407

出版商:John Wiley&Sons, Ltd.    

年代:1976

数据来源: WILEY

摘要:

AbstractMethyl nicotinate‐5‐2H was prepared in dry tetrahydrofuran by palladium‐catalyzed deuterolysis of methyl 5‐bromonicotinate. Acid hydrolysis of the crude reaction mixture resulted in a 92% yield of deuterium‐labeled nicotinic acid of which 80 mole% was nicotinic‐5‐2H acid and 12 mole% was nicotinic‐5‐2H acid containing an additional deuterium atom elsewhere in the molecule. The structure assignment was based on the results of nuclear magnetic resonance spectroscopy, mass spectroscopy, ultraviolet spectroscopy, and e

ISSN:0362-4803    

DOI:10.1002/jlcr.2580120408

出版商:John Wiley&Sons, Ltd.    

年代:1976

数据来源: WILEY

摘要:

AbstractThe synthesis of uvitic‐1,3,5‐13C acid, starting from Ba13CO3, is described. It allows the preparation of several compounds containing the aromatic and alicyclic six‐membered labelled ring on a micro scale with good y

ISSN:0362-4803    

DOI:10.1002/jlcr.2580120409

出版商:John Wiley&Sons, Ltd.    

年代:1976

数据来源: WILEY

摘要:

AbstractChloroacetaldehyde, which reacts selectively with cytosine and adenine nucleotides to give fluorescent etheno‐bridged derivatives, was synthesized bearing a14C label. The chloroacetaldehyde l‐14C, prepared from glycerol‐2‐14C, was used to form etheno‐bridged adenine and cytosine nucleotides for enzyme studies and was applied to the chemical modificatio

ISSN:0362-4803    

DOI:10.1002/jlcr.2580120410

出版商:John Wiley&Sons, Ltd.    

年代:1976

数据来源: WILEY

摘要:

AbstractA facile asymmetric synthesis of [C‐1‐3H]‐labelled (+)‐trans[1R,3R]‐chrysanthemic acid, required for biosynthetic studies is described. The tritium labelled acid is prepared from the corresponding (−)‐cis[1S,3R]‐ester by selective epimerisation of the C‐1 centre in the latter, in the presence o

ISSN:0362-4803    

DOI:10.1002/jlcr.2580120411

出版商:John Wiley&Sons, Ltd.    

年代:1976

数据来源: WILEY